Dees any recently SIP Server changes are made at VAPI. All of sudden our SIP Trunk with sip.vapi.ai stopped working with error message: Registration for "XXXXX"@sip.vapi.ai' timed out, trying again ..

Hi there! 👋 I don't have specific information about any SIP Server changes made at VAPI today (April 11, 2025), but I can definitely help with information about recent changes from the past few months and troubleshooting steps for your registration timeout issue. ### Recent SIP Server Changes at VAPI There have been a few notable changes to VAPI's SIP services in recent months: 1. Enhanced BYO SIP Trunk Configuration (November 21, 2024): VAPI added the ability to specify a

techPrefix

for outbound SIP calls and enable

sipDiversionHeader

for authenticating the calling number when configuring BYO SIP trunk credentials. [According to the changelog](https://docs.vapi.ai/changelog/2024/11/21). 2. New Transfer Plan Mode (January 5, 2025): VAPI added a new transfer plan mode (

blind-transfer-add-summary-to-sip-header

) that allows call summaries to be included in the SIP header during blind transfers. [According to the changelog](https://docs.vapi.ai/changelog/2025/1/5). 3. **Potential Service Disruption**: There have been some reports of issues with VAPI's SIP service recently, with one user reporting similar messages on calls. A VAPI representative indicated that the issue should be fixed, but another user mentioned facing the same issue for days. ### Common Causes for SIP Registration Timeout Errors Your error message "Registration for 'XXXXX'@sip.vapi.ai' timed out, trying again.." could be caused by several factors: 1. **Network Connectivity Issues**: Problems with network connectivity can prevent successful registration. 2. **Firewall Configuration**: Ensure your firewall is properly configured to allow SIP traffic and that there are no blocks on the ports used by SIP (typically port 5060). 3. **Authentication Problems**: VAPI expects authentication credentials in the Authorization header. The username must be your SIP username, and the password can be anything except "test".

Sounds like your being blocked or their SIP endpoint is faulty

Thanks Nir for the response on this tcase. That could be a reason but now the question is raised that how to request for a unblock 🙂 @Vapi , any suggetion to fix the issue?